recap-relay/server/test/credits.test.js

// Node-built-in test runner. Run with `node --test server/test/`.
//
// Targets the credit-key resolver added in the license-keyed-credits
// refactor. The headline guarantee: same license + different
// install_ids resolve to the SAME credit key. Plus a handful of
// adjacent cases worth pinning so the contract doesn't drift.

import { test } from "node:test";
import assert from "node:assert/strict";

import { getCreditKey, licenseFingerprint } from "../credits.js";

test("licenseFingerprint: stable hash from licenseUuid", () => {
  const fp1 = licenseFingerprint({
    tier: "pro",
    licenseUuid: "11111111-2222-3333-4444-555555555555",
  });
  const fp2 = licenseFingerprint({
    tier: "pro",
    licenseUuid: "11111111-2222-3333-4444-555555555555",
  });
  assert.equal(typeof fp1, "string");
  assert.equal(fp1.length, 16);
  assert.equal(fp1, fp2, "same licenseUuid should yield same fingerprint");
});

test("licenseFingerprint: different UUIDs yield different fingerprints", () => {
  const fp1 = licenseFingerprint({
    tier: "pro",
    licenseUuid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa",
  });
  const fp2 = licenseFingerprint({
    tier: "pro",
    licenseUuid: "bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb",
  });
  assert.notEqual(fp1, fp2);
});

test("licenseFingerprint: missing licenseUuid returns null", () => {
  assert.equal(licenseFingerprint(null), null);
  assert.equal(licenseFingerprint({ tier: "pro" }), null);
  assert.equal(licenseFingerprint({ tier: "pro", licenseUuid: null }), null);
});

test("getCreditKey: Core falls back to inst:<installId>", () => {
  const k = getCreditKey({
    installId: "abc-123",
    license: { tier: "core" },
  });
  assert.equal(k, "inst:abc-123");
});

test("getCreditKey: anonymous (no license) uses inst:<installId>", () => {
  assert.equal(getCreditKey({ installId: "xyz" }), "inst:xyz");
  assert.equal(getCreditKey({ installId: "xyz", license: null }), "inst:xyz");
});

test("getCreditKey: Pro license routes to lic:<fingerprint>", () => {
  const k = getCreditKey({
    installId: "any-install",
    license: {
      tier: "pro",
      licenseUuid: "11111111-2222-3333-4444-555555555555",
    },
  });
  assert.match(k, /^lic:[0-9a-f]{16}$/);
});

// Headline guarantee for the refactor: one license activated on two
// different installs MUST resolve to the same credit-key, so both
// devices share one Pro monthly pool.
test("getCreditKey: same license + different installs → same key", () => {
  const license = {
    tier: "pro",
    licenseUuid: "11111111-2222-3333-4444-555555555555",
  };
  const k1 = getCreditKey({ installId: "install-A", license });
  const k2 = getCreditKey({ installId: "install-B", license });
  assert.equal(k1, k2);
  assert.match(k1, /^lic:/);
});

test("getCreditKey: same install + different licenses → different keys", () => {
  const installId = "shared-install";
  const k1 = getCreditKey({
    installId,
    license: {
      tier: "pro",
      licenseUuid: "11111111-2222-3333-4444-555555555555",
    },
  });
  const k2 = getCreditKey({
    installId,
    license: {
      tier: "pro",
      licenseUuid: "99999999-9999-9999-9999-999999999999",
    },
  });
  assert.notEqual(k1, k2);
});

test("getCreditKey: Max tier also routes to lic:<fingerprint>", () => {
  const k = getCreditKey({
    installId: "any-install",
    license: {
      tier: "max",
      licenseUuid: "11111111-2222-3333-4444-555555555555",
    },
  });
  assert.match(k, /^lic:[0-9a-f]{16}$/);
});

// Paid tier with no resolvable fingerprint (license object missing
// licenseUuid) should defensively fall back to install-keyed rather
// than throwing or producing a phantom "lic:" key — keeps the ledger
// behaving correctly when the keysat verifier returns degraded data.
test("getCreditKey: paid tier without licenseUuid falls back to inst:", () => {
  const k = getCreditKey({
    installId: "ins-77",
    license: { tier: "pro" }, // no licenseUuid
  });
  assert.equal(k, "inst:ins-77");
});

test("getCreditKey: throws when neither installId nor a usable license is present", () => {
  assert.throws(
    () => getCreditKey({}),
    /installId required/i,
    "should throw on empty input"
  );
  assert.throws(
    () => getCreditKey({ license: { tier: "core" } }),
    /installId required/i,
    "should throw on Core license with no installId"
  );
});